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Educating the Student Body
imaging (MRI) in 55 healthy older adults aged 55-79. They observed 
robust age-related decreases in tissue density in the frontal, temporal, and 
parietal regions using voxel-based morphometry, a technique used to assess 
brain volume. Reductions in the amount of tissue loss in these regions 
were observed as a function of fitness. Given that the brain structures most 
affected by aging also demonstrated the greatest fitness-related sparing, 
these initial findings provide a biological basis for fitness-related benefits to 
brain health during aging. 
In a second study, Colcombe and colleagues (2006) examined the 
effects of aerobic fitness training on brain structure using a randomized 
controlled design with 59 sedentary healthy adults aged 60-79. The treat-
ment group received a 6-month aerobic exercise (i.e., walking) interven-
tion, while the control group received a stretching and toning intervention 
that did not include aerobic exercise. Results indicated that gray and white 
matter brain volume increased for those who received the aerobic fitness 
training intervention. No such results were observed for those assigned to 
the stretching and toning group. Specifically, those assigned to the aerobic 
training intervention demonstrated increased gray matter in the frontal 
lobes, including the dorsal anterior cingulate cortex, the supplementary 
motor area, the middle frontal gyrus, the dorsolateral region of the right 
inferior frontal gyrus, and the left superior temporal lobe. White matter vol-
ume changes also were evidenced following the aerobic fitness intervention, 
with increases in white matter tracts being observed within the anterior 
third of the corpus callosum. These brain regions are important for cogni-
tion, as they have been implicated in the cognitive control of attention and 
memory processes. These findings suggest that aerobic training not only 
spares age-related loss of brain structures but also may in fact enhance the 
structural health of specific brain regions.
In addition to the structural changes noted above, research has investi-
gated the relationship between aerobic fitness and changes in brain function. 
That is, aerobic fitness training has also been observed to induce changes 
in patterns of functional activation. Functional MRI (fMRI) measures, 
which make it possible to image activity in the brain while an individual 
is performing a cognitive task, have revealed that aerobic training induces 
changes in patterns of functional activation. This approach involves infer-
ring changes in neuronal activity from alteration in blood flow or metabolic 
activity in the brain. In a seminal paper, Colcombe and colleagues (2004) 
examined the relationship of aerobic fitness to brain function and cogni-
tion across two studies with older adults. In the first study, 41 older adult